Hand truck



HAND TRUCK 2 Sheets-Sheet l Filed May 31, 1955 9 4 2 v r 8 7 5 0 O m r n 4 e 3 3 O@O n q W O O r J/ \h w fim r w m 4 A. h r w 0 w M. J V V 9 5 4 W 4 fl \E kw 0 \4 M L w W 6 3 Q a m A: E l 3 M P W a y J1me 1957 J. A. FRIEBURGER 2,794,554

HAND TRUCK Filed May 51, 1955 I 2 Sheets-Sheet 2 fig. 4.

E,.. v DJ r lnzgmgr loss oh A. Frieb urg e r Afforney HAND TRUCK Joseph A. Frieburger, Grand Rapids, Mich. Application May 31, 1955, Serial No. 511,982 I 2 Claims. (Cl. 214378) This invention relates to the construction of l1andtrucl s used to transport heavy or merely bulky articles over short distances. devices includes a frame providing a supporting surface, a set of wheels adjacent to one end of the frame, a lifting plate for insertion under the edges of articles to be carried, and a handle at the opposite end of the frame from the wheels with which the device is manipulated. In operation, the unit is ordinarily brought up to a box or carton, and the lifting plate inserted under the edge-of the carton by rocking the carton back to a slight degree. The carton and the truck are then rocked in the opposite direction together, resulting in bringing the center of gravity of the loaded lift truck sufiiciently close to directly above the wheels that the load can be controlled conveniently by the handles. In this position, the unit can easily be wheeled from one place to another without excessive effort.

This invention provides an arrangement which permits a stacked group of cartons or packages to be picked up as a unit by the truck through the application of a clamping action applied to the load at the upper part of the frame. It is preferable that the cartons or boxes handled by the vehicle should determine the location of the clamping members such that the actual clamping surface could span the plane separating the stacked articles. If the clamping action is sufficiently strong with respect to the weight of the load, it is even possible to dispense with the conventional lifting plate at the bottom of the hand truck. The invention also provides a manner of controlling and locking the clamping system.

The several features of the invention will be analyzed in detail through an analysis of the particular embodiments illustrated in the accompanying drawings. In the drawings:

Figure 1 presents a side elevation of a hand truck loaded with two superimposed cartons, the lowermost of which is engaged by the lifting plate of the hand truck.

Figure 2 presents a top view in section on the plane of 2-2 of Figure 4.

Figure 3 is a section on an enlarged scale of the plan 33 of Figure 4.

Figure 4 is a fragmentary view on an enlarged scale showing the clamping and locking mechanism.

Figure 5 is a plan view similar to that of Figure 4, but with the handle lever and locking mechanism removed to expose the details of the mounting of the clamping members.

Referring to the drawings, a hand truck generally indicated at is formed by a frame 11 provided with wheels 12, a handle 13, and a lifting plate 14. The carton-s 15 and 16 are shown in position ready for the loaded unit to be rocked in a clockwise direction as shown in Figure 1 into a position in which the combined center of gravity is sufliciently close to directly above the axis of the wheels 12 that the unit can be controlled conveniently by a man holding the handle 13. An auxiliary support 17 is pro- Essentially, the standard form of these 2,794,564 Patented June 4, 1957 ice padding material as indicated respectively at 22 and 23.

Preferably, the clamping members 18 and 19 are also fitted with pads shown at 24 and 25 for providing additional support to the articles as they are transported.

- Referring particularly to Figure 5, the clamping members 18 and 19 are each provided with a beam as shown at 26 and 27 having sliding engagement with openings respectively indicated at 28 and 29 in the frame 11. The inner extremities of beams 26 and 27 terminate in rack portions 30 and 31, respectively, which are confined between the gear 32 interposed between them. Rotation of the gear 32 will induce clamping and separating of the plates 20 and 21, depending upon the direction of rotation.

The control of the clamping mechanism is applied 1 through the use of the handle lever 35, rotatably mounted on the end of the shaft 36 which supports the gear 32 Preferably, the gear 32 is machined integrally with the shaft 36, as in the illustrated form of the invention. The mounting of the handle lever 35 on the pin 37 at the end of the shaft 36 permits rotation of the handle lever on an axis perpendicular to the axis of the shaft 36, but fixes the handle lever 35 against rotation with respect to shaft on the axis of the shaft 36 itself.

A plate 38 is provided with a cylindrical extension 39 coaxial with respect to the shaft 36, for the support of the bearing 40 held in position by the set screw 41. The plate 38 is fixed with respect to the frame 10 by bolt-nut assemblies as indicated at 42 in Figure 3.

In addition to the support of the shaft 36, the plate 38 provides an annular group of discontinuities indicated at 43, which are arranged concentrically with respect to the axis of the shaft 36. A locking member 44 is secured to the handle lever 35 by the nut 45, and the oscillation of the handle lever 35 about the pin 37 causes the engagement and disengagement of the locking member 44 from the discontinuities 43. The handle lever is biased in a direction to bring the locking member 44 into engagement with the discontinuties 43 to lock the clamping members into position by the action of the spring 46 which tends to drive the plunger 47 toward the plate 38 on the opposite side of the shaft 36 from the locking member 44. With this arrangement, the operating handle 49 at the outer end of'the handle lever 35 may be used to rotate the shaft 36 to generate the desired degree of clamping or release of the clamping members 18 and 19, and the operating handle 49 may then be positioned to appropriately engage the locking member 44 with the discontinuities 43. The action of the spring 46 and the plunger 47 will serve to maintain such engagement until further manipulation of the operating handle 49.

Preferably, an auxiliary plate 50 is secured to the frame 11 of the hand truck, and is provided with a bearing 51 for receiving the end of the shaft 36. The rails 33 and 34 are secured directly to the plate 50, and the cover plate 52 is preferably applied to maintain the position of the rack portion 30 and 31 with respect to the gear 32.

The particular embodiments of the present invention which have been illustrated and discussed herein are for illustrative purposes only and are not to be considered as a limitation upon the scope of the appended claims. In these claims, it is my intent to claim the entire invention disclosed herein, except as I am limited by the prior art.

I claim:

1. A hand truck, comprising: a frame; clampingmem- I said rack portions; a shaft supporting said gear; 311511 01 tatably mounted on said frame; a handlelever mounted on said shaft and rotatable with respectthereto on; an axis perpendicular to the axis of said shaft, said handle lever being fixed against rotation with respect to said shaft about the axis of said shaft, a platefixed with respect to said frame and having an annular-group of discontinuities concentric with saidshaft; a-locki'ng-me'rnber fixed with respect to said handle lever'a'ndengage able and disengageable with said discontinuities 'onrotation of said handle lever With respect to said shaft; and biasing means including a plunger slideably-mounted on said handle lever for movement toward and away from said plate on the oppositeside OfSSidjSl'lQft from said'locking' member, and also including a "spring urging said plunger against said plate'and also urging said Handle lever to a position corresponding to engagementofs'a'id locking member with said discontinuities to'niaintain the clampingtaction'of said clamping members. 7 I

' 2. A hand truck, comprising?a'frame;'clampinginembers slideably mounted 'at opposite sides 'of said'frame for relative approaching andseparating movement, said "cla'inping'meinbers each having respectively overlapping rack portions; gear means engaging .saidv rack portions; a shaft supporting said gear means and rotatably mounted on said frame; a handlelever mounted on said shaft and rotatable with respect thereto on an axis perpendicular to the axis of said shaft, said handle lever being fixed against rotation with respect to said shaft about the axis of said shaft; means forming an annular group of discontinuities concentric with said shaft and an annular bearing surface transverse to the axis of said shaft; a locking member fixed with respect to said handle lever and engageable and disengageable with said discontinuities on rotation of saidhandle lever'with'respectjto said shaft; and biasing means including a plunger slideably mounted on said handle'lever for movement toward and away from said bearing surface on the opposite side of said shaft from said locking member, and also including a spring urging said plunger against said bearing surface and also urging said handle lever 'to a position corres'ponding to engagement of said "locking member with said discontinuities to maintain the clamping action of said clamping members.

References Cited in thefile of this patent UNI TED STATES PATENTS Kesling- Aug. 19, 1952 

